Zach Lowe talks Terrence Ross/ Raptors on SI.com

LAS VEGAS — Raptors coach Dwane Casey knows that when he talks about the skills and limitations of first-round pick Terrence Ross, it sounds as if he could be talking about DeMar DeRozan.

“It’s funny,” Casey said. “With both guys, the biggest chink in the armor is the need to get stronger and being able to fight for space and create off the dribble. They’ll both need to be in that weight room.”

Casey will never say it directly, but the Raptors’ drafting of Ross was a clear signal that the organization is ready to move on from DeRozan next summer if he doesn’t develop, or if his price in restricted free agency climbs too high. The Raptors are on pace to have a decent chunk of cap room — something like $10 million — even after overpaying for Landry Fields. But they could have max-level room without DeRozan’s cap hold, and given that DeRozan is still just 22 with room to grow, he may be in line for one of those four-year, $28 million deals that can hamper a team’s flexibility. Smart organizations understand the value of replacing so-so veterans with nearly equivalent players on rookie deals. That was the driving force behind San Antonio’s surprising George Hill-for-Kawhi Leonard trade, though that deal was even sweeter from the Spurs’ perspective since Leonard filled a positional need.

Casey swears that the Raptors didn’t draft Ross for this reason. “We didn’t necessarily look at Terrence as someone who would replace DeMar,” he told SI.com in Las Vegas during the summer league. “I haven’t thought about that at all. We just needed a shooter. We need as much shooting as we can get.”

Casey does concede that Ross will push DeRozan for playing time (“They’ll be battling for minutes,” he said), however, as both project as shooting guards more than small forwards when given traditional positional designations. But Casey prefers the generic term “wing” and says that Ross and DeRozan could play significant minutes together against the right opponents. That said, Landry Fields is now penciled in as the team’s starting wing alongside DeRozan, according to Casey.

Ross probably didn’t help himself with his play in Vegas, where he averaged 14.5 points on just 26-of-70 (37 percent) shooting, including an ugly 6-of-24 line from three-point range. But shooting is fickle, and Casey isn’t concerned. He’s thrilled, in fact, with Ross’ progress on defense. It’s clear watching Ross that he already has learned how to defend the pick-and-roll from various places around the floor. When he’s guarding a shooter in the corner, Ross understands when he needs to stay at home and when he needs to crash into the lane, bump the screener rolling to the rim and then retreat back to his original man. That sounds easy — help on the open guy! — but Casey says rookies rarely grasp the concept as quickly as Ross has.

“It’s one of the hardest things for a rookie to get,” Casey said. “They fall asleep.”

Point guards in the NBA are very good at switching the direction of a pick-and-roll, first going right, then crossing back and using the same screener to go left. Those little shifts change what someone in Ross’ position in the corner is supposed to do, and Ross can read that stuff already.

“I honestly didn’t know that about him when we drafted him,” Casey said. “I see it now.”

Ross looks like he’s going to be a feisty defender. He bumps those big guys hard and he’ll fight them for rebounds in the paint. He won’t always box out his own man with that same vigor, and he has an occasional tendency to reach for balls instead of maintaining good position. But scouts and executives in Vegas agree that he projects as a good defender. The consensus seems to be that Ross won’t be a star, but that he should be a very productive starter on a good team.

DeRozan has been an average defender at best, and a subpar shooter from the wing. When Casey says that the team needs “as much shooting as we can get” to space the floor, he’s talking about DeRozan and the rest of Toronto’s wing rotation. Incumbent point guard Jose Calderon is a very good shooter. Kyle Lowry, the bulldog defender who will jump Calderon in the rotation, has developed into an above-average long-range threat. Andrea Bargnani, for all his faults, is an elite big man shooter.

DeRozan is not. Despite a hot start from three-point range to begin last season, he quickly fell back to his normal levels, finishing at just 26 percent from three-point range and 35 percent (40 is the league average) on long two-point jumpers. His development as an off-the-dribble threat also stalled. Casey actually took the ball out of DeRozan’s hands a bit, cutting the number of DeRozan isolations and pick-and-roll plays from the 2010-11 season, per the stat-tracking service Synergy Sports. Instead, he had DeRozan run off a lot of sideline picks, hoping that catching the ball on the move would unleash a consistently effective off-the-bounce game in a way that high pick-and-rolls haven’t.

The results were hit-and-miss, in part because of DeRozan’s shaky shooting. Things were better when Bargnani was healthy and able to draw attention from defenders, thus opening up cleaner lanes for the other Toronto players to exploit. The Raptors scored at an average rate when Bargnani was on the floor and at a near-Bobcats-level when Bargnani sat, per the NBA.com stats database.

Ross has been running those same plays here, and he looks very comfortable catching-and-shooting anywhere from the three-point arc to the foul line. He also does well reading defenders and changing his cuts accordingly. When he spots a defender cheating toward the foul line, Ross will fake his normal curl, stop on a dime and cut backdoor. That will serve him well in the NBA, as players often defend those curl plays jumping the cut.

Putting the ball on the floor is a different story. Ross looks uneasy in that regard, rarely turning the corner on pick-and-rolls and settling for awkward floaters when he does. That sounds a lot like DeRozan again, something that’s not lost on Casey.

“The next step in the evolution for both of them is running the pick-and-roll and having an impact that way,” he said.

If DeRozan doesn’t make a significant leap this season, the Raptors will have a very interesting decision on their hands — and a decision that Ross can hugely influence with his play.

The controversy starts already. :S

A few other Toronto notes:

• Casey, a defense-first coach, was ecstatic when he learned that the team had a chance to nab Lowry in exchange for a first-round pick. Casey coached Randy Foye during his time as an assistant in Minnesota, and he remembered Foye, Lowry’s college teammate at Villanova, raving about Lowry’s crazy toughness.

• Casey has been in regular touch with Jonas Valanciunas, the Lithuanian center Toronto selected with the No. 5 pick in the 2011 draft. Casey last saw Valanciunas a few weeks ago in Houston, where the Lithuanian national team was training in advance of an Olympic qualifying tournament.

Valanciunas spent last season playing professionally in Lithuania, but he’s coming to Toronto this season, and Casey says he expects Valanciunas to seize a major rotation role immediately. “He’s been playing against grown men,” Casey said, “and they eat their young over there.”

If Valanciunas does snag that kind of role, both Amir Johnson and Ed Davis will be on notice, though the Raptors’ trade of James Johnson to Sacramento last week removed one body from the team’s big man competition. Johnson has played both forward positions, but Casey says the team projected him mostly as a small-ball power forward. Linas Kleiza has played that role before in both Denver and Toronto.

• Casey’s goal for the team is to make the playoffs this season. “I’m not going to guarantee it,” he said, “but it’s a goal. The goal is always to build something, and keep improving. I think it’s a definite possibility.”

I like the fact that when asked if the team drafted Ross with the intention of maybe replacing DD, Casey said “We didn’t necessarily look at Terrence as someone who would replace DeMar,” That tells me that they had that in the back of their mind. Sneaky but good move. Little competition will do DD good.